NetBSD/sys/miscfs/syncfs/sync_vnops.c

216 lines
5.4 KiB
C

/* $NetBSD: sync_vnops.c,v 1.3 2000/07/09 00:59:06 mycroft Exp $ */
/*
* Copyright 1997 Marshall Kirk McKusick. All Rights Reserved.
*
* This code is derived from work done by Greg Ganger at the
* University of Michigan.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. None of the names of McKusick, Ganger, or the University of Michigan
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY MARSHALL KIRK MCKUSICK ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL MARSHALL KIRK MCKUSICK BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/errno.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/syncfs/syncfs.h>
int (**sync_vnodeop_p) __P((void *));
struct vnodeopv_entry_desc sync_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_close_desc, sync_close }, /* close */
{ &vop_fsync_desc, sync_fsync }, /* fsync */
{ &vop_inactive_desc, sync_inactive }, /* inactive */
{ &vop_reclaim_desc, sync_reclaim }, /* reclaim */
{ &vop_lock_desc, sync_lock }, /* lock */
{ &vop_unlock_desc, sync_unlock }, /* unlock */
{ &vop_print_desc, sync_print }, /* print */
{ &vop_islocked_desc, sync_islocked }, /* islocked */
{ (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
};
struct vnodeopv_desc sync_vnodeop_opv_desc =
{ &sync_vnodeop_p, sync_vnodeop_entries };
/*
* Create a new filesystem syncer vnode for the specified mount point.
*/
int
vfs_allocate_syncvnode(mp)
struct mount *mp;
{
struct vnode *vp;
static long start, incr, next;
int error;
/* Allocate a new vnode */
if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0)
return (error);
vp->v_writecount = 1;
vp->v_type = VNON;
/*
* Place the vnode onto the syncer worklist. We attempt to
* scatter them about on the list so that they will go off
* at evenly distributed times even if all the filesystems
* are mounted at once.
*/
next += incr;
if (next == 0 || next > syncer_maxdelay) {
start /= 2;
incr /= 2;
if (start == 0) {
start = syncer_maxdelay / 2;
incr = syncer_maxdelay;
}
next = start;
}
vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0);
mp->mnt_syncer = vp;
return (0);
}
/*
* Destroy the filesystem syncer vnode for the specified mount point.
*/
void
vfs_deallocate_syncvnode(mp)
struct mount *mp;
{
struct vnode *vp;
vp = mp->mnt_syncer;
mp->mnt_syncer = 0;
vn_syncer_remove_from_worklist(vp);
vp->v_writecount = 0;
vgone(vp);
vrele(vp);
}
/*
* Do a lazy sync of the filesystem.
*/
int
sync_fsync(v)
void *v;
{
struct vop_fsync_args /* {
struct vnode *a_vp;
struct ucred *a_cred;
int a_flags;
struct proc *a_p;
} */ *ap = v;
struct vnode *syncvp = ap->a_vp;
struct mount *mp = syncvp->v_mount;
int asyncflag;
/*
* We only need to do something if this is a lazy evaluation.
*/
if (!(ap->a_flags & FSYNC_LAZY))
return (0);
/*
* Move ourselves to the back of the sync list.
*/
vn_syncer_add_to_worklist(syncvp, syncdelay);
/*
* Walk the list of vnodes pushing all that are dirty and
* not already on the sync list.
*/
simple_lock(&mountlist_slock);
if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock) == 0) {
asyncflag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
VFS_SYNC(mp, MNT_LAZY, ap->a_cred, ap->a_p);
if (asyncflag)
mp->mnt_flag |= MNT_ASYNC;
vfs_unbusy(mp);
} else
simple_unlock(&mountlist_slock);
return (0);
}
/*
* The syncer vnode is no longer needed and is being decommissioned.
*/
int
sync_inactive(v)
void *v;
{
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
VOP_UNLOCK(vp, 0);
if (vp->v_usecount == 0)
vgone(vp);
return (0);
}
int
sync_reclaim(v)
void *v;
{
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
int s;
s = splbio();
vp->v_mount->mnt_syncer = NULL;
LIST_REMOVE(vp, v_synclist);
splx(s);
return 0;
}
/*
* Print out a syncer vnode.
*/
int
sync_print(v)
void *v;
{
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
printf("syncer vnode");
if (vp->v_vnlock != NULL)
lockmgr_printinfo(vp->v_vnlock);
printf("\n");
return (0);
}